Obama called the four-term senator "one of my favorite people in either Washington" and described her as a lawmaker who gets things done without a lot of drama and fuss.

The seat is considered a safe one for Democrats. But Murray is leaving nothing to chance, particularly after her narrow victory with just 52 percent of the vote in 2010, her closest Senate contest yet.

At the same time, Obama is seeking to impress upon voters progress that he says the U.S. has made during the nearly seven years of his presidency.

Musing on the GOP candidates who are vying to win his job next year, Obama said: "Why are all these Republicans so down on America? Listening to them is really depressing and it doesn't match up with the truth."

Earlier Friday, Obama was somber and soft-spoken after meeting in Oregon with the families of victims of a mass shooting at a community college. But he returned with passion to the gun issue during the Murray fundraiser.

Bemoaning the many shooting sprees the nation has experienced in recent years, the president said: "It is not normal. It is not inevitable. It does not have to happen. There are ways to protect our children and protect our rights."

Obama later flew to California, where he'll attend several fundraising events over the weekend.